Two ships bearing troops from Newfoundland and Labrador, a colony of Great Britain (and later a province of Canada) joined the initial convoy of North American transports carrying 25,000 soldiers to Europe to join Britain's war effort. The convoy arrived in Britain in October 1914.

Some of the heaviest casualties on July 1, 1916, the first day of the Battle of the Somme were suffered by the Newfoundland Regiment. Combined British forces suffered 60,000 casualties, 19,240 of them dead, the greatest one-day loss for any army during the war. The Newfoundland Battalion lost 91% of its men in 40 minutes.

Newfoundland losses extended to the Mercantile Marine and the Naval Reserve.